Premium
Evaluation of tissue oxygen saturation of the masseter muscle during standardised teeth clenching
Author(s) -
Satokawa Chiho,
Nishiyama Akira,
Suzuki Katsuhiko,
Uesugi Shunsuke,
Kokai Satoshi,
Ono Takashi
Publication year - 2020
Publication title -
journal of oral rehabilitation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.991
H-Index - 93
eISSN - 1365-2842
pISSN - 0305-182X
DOI - 10.1111/joor.12863
Subject(s) - masseter muscle , medicine , repeated measures design , oxygen saturation , oxygenation , anesthesia , cardiology , anatomy , chemistry , mathematics , oxygen , statistics , organic chemistry
Background Haemodynamics during recovery after teeth clenching is poorly understood. Objective To clarify factors influencing tissue blood oxygenation recovery after clenching with altered muscle activity and duration, but constant total muscle activity. Methods The following tasks were based on constant maximum voluntary clenching (100% MVC): (a) 50% MVC × 30 seconds; (b) 30% MVC × 50 seconds; and (c) 10% MVC × 150 seconds. Tissue oxygenated (oxy‐Hb), deoxygenated (deoxy‐Hb) and total haemoglobin (total‐Hb) were recorded using near‐infrared spectroscopy in the masseter muscle during recovery after each task. Participants rested for 30 seconds before each task; average resting values were set as baseline. Respective ratios to baseline at 20, 60, 120 and 180 seconds after each task were calculated; the tasks were compared at each time point using one‐way repeated‐measures ANOVA. Results Oxy‐Hb and total‐Hb decreased and deoxy‐Hb increased during the tasks and recovered thereafter. For Task 3, not all values recovered to baseline, even after 180 seconds (oxy‐Hb: 96.85%, total‐Hb: 98.31%, deoxy‐Hb: 102.98%). Oxy‐Hb (after 180 seconds, Task 1‐Task 3: P < .001, Task 2‐Task 3: P = .013) and total‐Hb (after 180 seconds, Task 1‐Task 3: P < .001, Task 2‐Task 3: P = .005) were significantly lower, and deoxy‐Hb (after 180 seconds, Task 1‐Task 3: P < .001, Task 2‐Task 3: P = .005) was significantly higher for Task 3 than other tasks, at all times during and after recovery. Conclusion Despite the same total muscle activity, weak‐force, long‐duration clenching is more harmful than strong‐force, short‐duration clenching, suggesting a greater effect of awakening bruxism than sleep bruxism on myalgia.